thomson



2 Sheets--Sheet'x 1.

R.,D.TH0MS0N.

Mower.

No. 195,907. Patented oct. 9, 1877.

2 Sheets-Sheet 2.

R. D.'THOMSON.

Mower.

No. 195,907. Patented Oct. 9, 1877.

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Nrrnn :STATES ROBERT D. THOMSON, OF NORTH PLATTE, NEBRASKA, ASSIGNOR T() THOMSON M-OWING MAOIIINE COMPANY.

IM'PROV'EM ENT IN MOWERS.

Specification forming part of Letters Patent No. 195,907, dated October 9, 1877; application tiled April 9, 1877.

To all whom it may concern:

Be it known that I, ROBERT D. THOMSON, of North Platte, Lincoln county, Nebraska, have invented new and useful Improvements in Mowers and Reapers; and I do hereby declare that the following is a full, clear, and eX- act description ofthe same, reference being had to the drawings herewith, in which- Figure l is a plan view. Fig. 2 is a section on the line w cc, Fig. 1. Fig. 3 is a section on the line y y, Fig. 2. Fig. 4 is a sectional view of one of the guards. Fig. 5 is an elevation of the knife-bar head. Fig. 6 is the knife-barhead bushing. Fig. 7 is the pattern or blank77 of the bushing. Fig. 8 is a sectional view on the line z z of Fig. 9; Fig. 9, the section or knife.

My invention consists in the construction of a guard adapted to be used in combination with sections or knives, and in a blank or pattern for a sheet-metal bushing, and in the manner of adapting such bushing to a knife-bar head, also adapted for its reception and retention.

To enable those skilled in the art to make and use my invention, I proceed to a more particular description of its parts and their operation.

A is the knife-bar, which is provided with a screw or lug for the attachment of the spring B C. The said screw or lug passes downward into the center of the spring, which operates to balance the knife-bar in such a manner that the shock occasioned by a change in the direction of its movement is overcome.

This spring, as is illustrated in Fig. 3, is seated in a recess formed beneath the knifebar head D in the shoe, in such manner that the ends of the spring are attached to the shoe and its center to the screw or lug on the knifebar.

D is the knife-bar head, and is provided with a sheet-metal bushing, E, of copper or brass, or other suitable sheet metal, cut in the shape shown at Fig. 7, and formed as shown at Fig. 6. This bushing is provided with the apertures a a extending into the blank beyond the lines of folding, c' c'. These apertures form a passage for the oil to the pitman-bolt by means of the oil-hole c.

The lianges formed by folding the blank, as shown, are inserted in the slot (l ot the knifebar head, which prevents the bushing from turning' Within its bearing.

F are the knives, and they are provided with cutting-edges formed by a smooth equal bevel on the upper and under side, shown at Fig. S, thus 'affording a cutting-edge, for which the guards Gr are adapted by being formed Without cutting-edges, which are provided in the usual construction of guards by the addition of a ledgerplate of steel, and which has the disadvantage of not only expense, but of liability to come in contact with the knives when in Operation and dull them.

The edges of the guards are formed without means for cutting, but simply to operate as resisting-edges to the operation of the knives against the erop. The guards G are also adapted to operate in a more satisfactory manner by being constructed with regard to the size of whatever knives they are used with, in that they have a width at their bases and an outline or contour at their sides at the poition traversed by the knives similar to such knives, and also have their sides extended to form a point.

Furthermore, the guards are integral, and have upon the under side and at the rear of their caps a projection, which serves to bear upon the rear portion ofthe upper surfaces ot' the knives, and keep them in place while in operation. They also have a slot ot' sufficient depth to allow of a vibration vertically of the front portions of the knives without impinging against the guards.

This construction of the guards permits ot' their being made of cast-iron, which reduces the cost of their production.

By forming their bases and sides similar in dimension and contour with the knives, a resisting-edge is offered to the knife from themstant it begins its reciprocative movement, and continues until the point of the knife passes within the guard, thus obviating the necessity of a number (two or more) of reciprocative movements of the knives during the advance of the machine to a distance equal to the length of the knives. This is accomplished by one movement of my knives.

In a measure. the bent-tit ot' :i eomplete eut eun be obtained in the use ot' my gunrd in eombinution with knives whose edge is formed by :L bevel on one side only. but in u greater degree by the use ot' the knife eonstrueted ns shown :1nd hereinbetbre deseribed. while with single-beveled knives eollisions oeeur with the guards.

The operation ot' my invention is obvious. Uonneetion is mude with the operative parts 0i' the mower by suitnble menus nt the knife bar head. A movement ot' the knit'e-bnr from u stilte of rest is met by the resistunee ot' the lmlaneing-spring. whieh resistnnee inerenses :is the bur nenrs the limit ot' its throw, where the spring overemnes the shoek ot' u ehnnge in the direetien ofthe movement ot' the bnr. At the salue time the knives nre :u their start met with a resisting-edge in the gunrds. und they eontinue sueh resistunee throughout the entire length of the eutting-edge ot' the knit'e. The operation of the springs und ot' the guurds is repeated upon the return movement otl the bnr.

I claim.-

1. The sheet-metallbushing blnnk E. provided with the slots a a', extending inwardly beyond the line of folding, substantially :1s shown :1nd deseribed.

2.. 1n eombination with the knife-bur head of a mower or reaper, a. sheet-metal removable bushing` provided with a 1eteinng ;lang(l lu1ving slots therein, as shown and described.

3. An integral guard whose sides or edges :1re non-cutting, similar in contour or outline to the knife with which it is used, und extended to t'orm its point, und Whose cap is provided with :i projet-,tion upon the rear ot' its under side, :is shown :1nd described.

4. In a mower or reaper, the combination ot' u knit'e whose cutting-edge is formed by un equal smooth bevel 011 its upper and under side with un integral guard whose sides are non-eutting and of like outline 0r conteur t0 those ot' the knife, and extended to form n point, ns shown .md described.

R. I). THOMSON.

\`\'itnesses:

JNo. ll. Cook, li. 'l'. tLosn. 

